Machine tool



March 1-7, 1942. H. F. PATRICK MACHINE T001.-

Filed Aug..17, 1939v 5 Sheets-Sheet 1 March 17, 1942. F, PATRlcK 2,276,625

MACHINE TOOL Filed Aug. 17. 1959 5 sneets-shet 2 March 17,- 1942. H. F. PATRICK MACHINE TOOL Filed Aug. 17,Y 1939 5 Sheets-Sheet`3 TTOQLEYS March V127, 1942. H. F. PATRICK MACHINE TOOL Filed Aug. 17, 1959' 5 Sheets-Sheet 4 i K may/s Qu "QQ March 17, 1942.

H. F. PATRICK Y2,276,625

MACHINE Tooll' Filed Aug. 17, 1959 5l sheets-smet 5 @ll/e@ 62290/5706 l x T-romays Patented Mar. 1 7, 1942 MACHINE TOOL Henry F. Patrick, Rockford, Ill., 4 assignor to Mattison Machine Works, Rockford, Ill., a corporation of Illinois Application August 17, 1939, Serial No. 290,538

y 21 claims. (Cl. 5192 l 'I'he present invention relates to improvements in machine tools, and has particular reference to a new and improved metal removing machine, such as a grinding machine, in which the tool is adapted to take a series of cuts along the work, and to be indexed transversely of the work for successive cuts. y

One of the objects of the present invention is to provide a machine tool of the foregoing character having novel hydraulic means for automatically effecting a relative indexing of the tool across the work in a step-by-step movement.

Another object is to provide a new and improved hydraulic indexing mechanism in which the'extent of each indexing movement is subject to a finely graduated adjustment .over a wide range.

Fig. 9 is a diagrammatic respresentation of the hydraulic and electrical control circuits for the A further object is to provide a hydraulic in-v dexing mechanism including a novel -indexing control valve which is normally open to relieve the motive iiuid pressure, and adapted to be closed periodically to maintain the pressure for a predetermined time interval to eiect the indexing movement, and-which is operable with a quick action alternately into open and closed positions to prevent coasting or indeterminate `movement of the indexed element.

A more specic object resides in the provision of a novel electrical control means for the indexing control valve.

Another object -resides in the provision of means available at will for obtaining either a step-by-step indexing movement, a rapid continuous indexing movement, or a slow continuous indexing movement'.

A further object is to provide a novel hydraulic indexing mechanism which is automatically operable to reverse the direction of indexing move ment upon movement of the indexed element into a predetermined position, but which upon the institution of such reversal after one cut along the work serves to delay completion of the reversal until after the next cut.

Further objects and'advantages will become apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a front perspective view of a machine embodyingI the features of my invention. .Y v

Fig. 2 is a fragmentary transverse vertical sec- .tional view through the machine.

Fig. 3 is an enlarged vertical sectionaly view taken substantially along line 3--3 of Fig. 4.

Fig. 4 is a fragmentary front view of the ma- V l machine.

Fig. l0 is a fragmentary horizontal sectional view taken along line III-I0 of Fig. 2.

Fig. 11 is a vertical sectional view taken along line II-II of Fig. 10.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the speciiic form disclosed, but intend to cover all modifications and alternative constructions falling Within the spirit and scope of the invention as expressed in the appended claims.

Referring'more particularly to the drawings, the invention, for purposes of illustration, is embodied in a grinding machine of the type disclosed in United States Letters Patent No. 1,927,007, dated September 12, 1933, adapted for the grind-- ing of plane surfaces. In the form shown, the grinding machine comprises a-long horizontal bed I'formed' on the top with parallel longitudinal ways 2. A work carriage 3, adapted to support the work to be ground, is suitably mounted for reciprocation on the ways 2.

Any suitable drive may be provided for reciprocating the work carriage 3. In the present instance, the drive (see Fig. 9) comprises two parallel hydraulic cylinders 4 and 5, the adjacent ends of which overlap and are rigidly connected, and

which are rigidly mounted within the bed I. Two i rams 6 and 1 of equal diameter are slidable respectively in the cylinders 4 and 5, and project in opposite directions from the adjacent ends of the cylinders for connection (not shown) to the underside of the work carriage 3. v

The outer or remote ends of the cylinders 4 and 5 are connected respectively through passages II and I2 to a direction valve I3. This valve comprises a casing I4 formed with a cylindrical valve chamber I5 and with two small chambers I6 and I1 opening axially to opposite ends thereof. A valve member I8 of the spool type is reciprocable in the chamber I5, and has axial reduced end extensions or plungers I9 and 20 extending slidably into the chambers I6 and Il. Formed in the chamber I5 are two exhaust ports 2l and 22 at the ends 'and'opening to an exhaust passage 23, an inlet port 24 midway of the exhaust ports and connectedl to a supplyg passage 25, and two ports 26 and 21 respectively intermediate the inlet port 24 and the exhaust ports, and connected to the passages II land I2. The arrangement is such that, in one end position of the valve member I8, the passages II and I2 are connected respectively to the exhaust and pressure passages 23 and 25, and, in the other end position of the member, the connections are reversed.

The supply passage is adapted to be connected through a start and stop valve 53 to a suitable source of iuid medium, such as the discharge line or passage 25L of a constant-pressure delivery pump 28 driven by an electric motor 29. The intake of the pump 28 is connected through a line or passage 30 to a supply tank or sump 3| adapted to contain a substantially noncompressible liquid, such as oil. Interposed in the pressure line 25 at the outlet side of the pump 28 is a relief valve 32 which is operable to discharge fluid. in excess of that required to maintain a predetermined pressure, to the exhaust conduit 23. The exhaust conduit 23 discharges to the sump 3|. An adjustable restriction oriiice 33 is interposed in the conduit 23 to maintain a relatively low back pressure.

The direction valve I3 is hydraulically adjustable under the control of a pilot valve 34 which comprises a cylindrical chamber 35 preferably Ialso formed in the casing I4. Opposite ends of the chamber 35 open to an exhaustline or passage 31 which discharges to the sump 3|. A pressure passage 39 opens to the chamber 35 midway of the ends, and is connected to asuitable source of iiuid medium, such as a constant-pressure delivery pump 40 also driven by the motor 29 and taking fluid from the sump 3|. Interposed in the conduit 39 is a relief valve 4| by-passing to the sump 3| and operable to limit the pilot pressure to a predetermined maximum preferably less than the pressure in the conduit 25. passages 42 and 43 open from the chamber 35 respectively at opposite sides of the conduit 39 to the closed outer ends of the chambers I6 and I1 of the direction valve I3. A. valve member 44 of the. spool type is slidable lin the chamber 35, and serves in one tencl position to connect the passages 42 and 43 respectively to the passages' 99 and 31 so as to cause movement of the direction valve member I8 to the right to effect movement of the carriage 3 to the left. and in the other end position to reverse these connections so as to reverse the direction valve to effect movement of the carriage to the right.

The pilot valve member 44 has an axial rod 45 which extends slidably through one end wall of the chamber 35, and which is connected at the outer end to one end of a lever 46 pivoted on the casing I4. The other end of the lever 46 is connected through a link 41 to a lever 48 pivotedon the front of the bed I, and formed with two arcuately spaced lugs 49 and 50. Two pivotal dogs 5|, adjustably mounted on the front of theY carriage 3, are adapted for alternate engagement respectively with the lugs 49 and 50 to effect reversal of the direction valve I3 upon movement of the carriage 3 respectively into` opposite end,

positions. 'I'he lever 48 is provided'with a handle 52 for effecting manual adjustment of direction valve I3 atwill.

The start and stop valve 53 comprises a valve member 54 slidable in the casing I4, and operable in oppositeend positions respectively to connect the passage 25a either to the passage 25 or the exhaust passage 23. One end of the valve member 54 is connected to one arm of a lever 55 pivoted on the front of the bed -I. the lever 55 is connected through a link 56 to a lever 51 also pivoted on the front of the bed I and provided with a handle 58. The lever 51 is adapted for engagement by a dog 51a, upon movement of the adjacent dog 5| into inoperative Another arm of position, to stop the machine. It will be seen that the valves I3, 34 and 54 are incorporated in a unitary valve structure including the casing I4. This structure is mounted on the front wall of the bed I, and is suitably enclosed by a front cover plate or housing II5 on which the levers 48 and 51 are pivoted.

Rigidly mounted on the rear of the bed I are two spaced vertical columns 59 and 60 connected at their upper ends by a cross member 6|. The adjacent sides of the columns 59 and 69 are formed with Vertical ways 62 and 63, on and between which a tool head 64 is mounted for vertical adjustment. The tool head 64 is supported for vertical adjustment by a feed screw 65 extending along the column 59 and operable from the front ofthe bed I by means of a hand Wheel 66.

Mounted von ways 61 on the underside of the tool head 64 between the columns 59 and.60 for adjustment transversely of the carriage 3 is a tool slide 68. A tool spindle 69 supporting a grinding wheel 10 is journaled in the slide 68, and adapted to be driven by an electric motor 1|.

The tool slide 68 is movable step-by-step across the work carriage 3 in timed relation to the reversals of the latter, and the power drive for this purpose includes a hydraulic motor consisting of a. cylinder 12 mounted on the tool head 64 and a piston 13 slidable in the cylinder and connected through a rod 14 to the rear end of the slide.

The opposite ends of the cylinder 12 are connected respectively through lines or passages 15 and 16 to a direction valve 11 controlled by a pilot valve 18. These valves comprise respectively two cylindrical bores or chambers 19 and 80 preferably formed in a single casing 8| mounted on the front of the bed I inside the front housing II5. The chamber 19 is formed with ve longitudinally spaced annular grooves 82 to 86, and the chamber is similarly formed with grooves 81 to 9|. The end grooves 82 and 86 of the valve 11 are connected through exhaust passages 92 and 93 to the end grooves 81 and 9|, and the latter are connected through an exhaust conduit or passage 94 to the sump 3|. Of the Valve 11, the grooves 83 and 85 open to the passages 15 and 16, and the central groove 84 opens to a pressure inlet line or passage adapted to receive liquid under pressure from the line or passage 39 through an index control valve 96. Slidably mounted in the chamber 19 is a valve member 91 of the spool type. This member serves in one end position to connect the passages 15 and 16 respectively to the pressure inlet passage 95 and the exhaust groove 86 to eiect indexing in a forward direction. In the other end position, the valve member 91 serves to connect the passages 15 and 16 respectively to the exhaust groove 82 `and the passage 95 so as to reverse the direction of indexing. In central or intermediate position, the v alve member 91 blocks both passages 15 and .16 from the passage 95.

Referring again to the pilot valve 18, the cenr tral or intermediate groove 89 is open to a preseure inlet line or passage 98 branching from the passage 25, and the grooves 88 and 90 are connected respectively through passages 99 and |00 to the outer ends of two small cylinder bores |0I and Y|02 opening axially to opposite ends of the direction valve chamber 19. Suitable pistons |03 and |04 extend axially from opposite ends of the direction valve member 91 respectively into the bores |0| and |02, Slidably mounted in the pilot valve chamber 80 is a valve member |05 of the spool type which in one end position serves to connect the passages 99 and |00 respectively to the .pressure and exhaust passages 98 and 94 and in the other end position serves to reverse these connections.

The pilot valve 16 is automatically operable tov reverse the direction valve 11 at each end of the cross feed movement'of the slide 68. Thus, the forward end of the valve member is pivotally connected to one arm of a bell crank lever |06 pivoted on the valve casing 3 I. 'Ihe other arm of the lever |06 is connected through a link |01 to an arm |08 fixed on a rock shaft |09jouma1ed in the front housing I I5. A hand lever I0 fixed on one end of the shaft |09 affords means for adjusting the pilot valve 18 manually. Also xed on the shaft |09 is a vertical rocker arm III adapted for alternate engagement atr ODpOsite sides by two angularly spaced cam levers I2 and I3 rotatable about a common axis in timed relation to the movement of the cross slide 68.

The cam lever ||2 is xed on the inner end of a tubular shaft ||4 journaled in and extending The cam lever II3 likewise is' fixed on the inner end of a tubular shaft I6 extending through and rotatable in the shaft I I4. Extending axially through the shaft ||6 is a drive shaft ||1 on the outer end of which a ratchet wheel I I8 is secured. Two arms I I9 and |20 rigid respectively with the outer ends of the shafts ||4 and ||6 are pro` vided with releasable detents |2| and |22 adapted for adjustable engagement with the ratchet wheel i ||8 to connect the cam levers ||2 and |I3 in different relative angular positions for rotation with Ythe shaft ||1.

The inner end of the shaft ||1 is connected, through gears |23 and |24 to a shaft |25 extending through the bed to the 4rea-r between the columns 59v and 60. The rear end of the -shaft |25 is connected through spiral gears |26 and |21 to the lower end of a vertical spline shaft |28 suitably anchored against endwise movement. A gear |29 rotatably mounted in the tool l head 64 for vertical movement therewith is splined to the shaft |28, and meshes with an idler gear |29a meshing with a longitudinal gear rack |30 on the side of the spindle slide 68.

It will be seen that upon forwardmovement 18 to direct pressure fluid into the passage 99.

sages and |36 to the exhaust grooves 82 and 86, and the intermediate groove |33 is open to an inlet passage I 31 connected to the pressure passage 39 through a' passage |38 including an adjustable restricted orifice |39. The passage |31 is also adapted to be connected to the passage 39 for the unrestricted supply of pressure fluid through a valve |40 in parallel with the orifice |39. This valve |40 comprises a casing |4| having a cylindrical chamber |42 with two spaced grooves |43 and |44 connected respectively to the passages |31 and |39, and a valve member |45 slidable in the chamber and having a recess |46 adapted in 'one'position to connect the grooves and in another position to interrupt communication therebetween.v The upper end of the valve member |45 is pivotally connected to an arm 41 on a shaft |48 mounted in the housing ||5, and provided at the front vwith, a hand lever |49. t

Slidably mounted in the chamber |3| of the valve 96 is a valve member |50 having an annular recess |5I. A snap ring |52 on one end of the valve member |50 is4 arranged for engagement with the casing 8| to dene one end position in which `the recess |5| establishes free communications between the inlet groove |33 -and the exhaust groove |34. The valve member I 50 is normally urged into this end position by suitable pressure means, such as a coil compression spring |53, seated in a recess |54 in an end plate |55 on the casing 8|. It will be evident that when the valve 96 is in open position as shown, pressure fluid will be by-passed directly to the exhaust -passage 94 through the chamber I3I, the

groove, |34, the passage |36, the groove 86, the passage 98 and the groove 9|, and hence no pressure for indexing the tool slide 68 will be available in the passage 95. However, when the valve member lso is/moved to the right against the action of the spring |53, the recess |5| will be moved out of communication with the groove |33 to block the by-pass through the chamber |3| to the groove |34 so that fluid under full pressure will be available in the passage to index the tool slide 68.

The index control valve 96 is adapted to be closed for a predetermined adjustable interval at each reversal of the work carriage 3. In the present instance, 9the means for this purpose comprises an electric solenoid |56 mounted on Thereupon, the direction valve 11 will be shifted..-

to direct pressure fluid through the passage 16 to the front of the cross feed cylinder 12 so as to institute a rearward or return cross feed of the slide 68. Similarly, at the end of the rearward index movement, the cam lever ||3 will rock the arm forwardly to vreinstitute the forward cross feed. The range and extent of the tool cross feed is, therefore, determined by the relative angularl adjustments of the cam- -leads from the main L1 through a line |59, a

master switch |60, a line |6I, the solenoid coil |56, a line |62, a normally open time delay switch |63 with yieldable contacts, anda line |64 to the main La. The switch |63 is normally held open by a spring |65, and is movable into lclosed position with the contacts in flexed position upon excitation of an actuating coil |66 adapted to be connected across the lines 6| and |64 by a normally open switch |61. A ldog |68 on the lever 46 is adapted in the course of itsoscillations upon each actuation of the pilot valve 34 to engage and close the switch |61 momentarily. opening of the switch |63 by the'spring las after each excitation of the coil |66 is suitably delayed for a desired period of time by a dash pot |69 which comprises a cylinder |10, a piston |1| in the cylinder and connected to the valve stem, a by-pass line |12 connecting opposite ends of the cylinder and including a manually adjustable throttle valve |13, and a p-arallel by-pass line |14 including a one-way check valve |15 permitting quick closing of the switch.

In operation, for normal intermittent indexing, the valve |40 is open. At each reversal of the work carriage 3, the dog |68 closes the switch |61 momentarily to effect closing of the switch- |63. This causes energization of the solenoid |56 which moves the by-pass valve 96 into closed position. The valve 96 remains closed until the time switch |63 opens, and thereupon is quickly returned to full open position. When the valve 96 is closed, pressure fluid from the pump 40 is directed to the cylinder 12 to effect cross indexing. The extent of each cross indexing movement or step is. therefore. dependent on the time interval during which the valve 96 is closed. This interval may be varied as desired by adjusting the throttle valve |13 of the dash pot |69. It will be seen that in each traverse of the work carriage 3, the grinding wheel takes a cut along the work. At the end of each cut, the grinding wheel 10 is indexed through a distance somewhat less than the width of its face so that in the next traverse of the carriage 3 in the reverse direction it will take a parallel contiguous cut. The carriage 3 is reciprocated and the grinding wheel 10 is indexed step-bystep in the foregoing manner until the entire work surface to be ground has been traversed. At this point, the indexing movement may be automatically reversed, and the operation continued to take a second cut on the work surface.

In some instances, the last cross feed movement to complete the indexing in either direction across the work may be less than the normal extent of indexing. Provision is made for preventing reversal of the valve 11 after a partial indexing movement until after the carriage 3 has completed a full traverse along the edge of the Work. The means for this purpose comprises two plungers |16 and |11 reciprocable in and |19 are enlarged to define pressure cham- .-f

bers connected to the pressure conduit 95. The

inner ends of the plungers |16 and |11 are beveled for camming engagement respectively with similarly beveled ends on the pistons |03 and |04. Suitable heads and |8| on the outer ends of the plungers |16 and |11 are adapted for engagement with the outer edges of the'bores |18 and |19 to limit inward movement of the plungers. When both plungers |16 and |11 are located in their inner-most positions, as shown in Fig. G, they act to locate the valve member 91 in neutral position in which the pressure groove 84 is blockedfrom the grooves 83 and to prevent cross indexing.

. In operation, the valve member 91 normally occupies one end position or the other.

Upon the institution of each cross indexing movement, the pressure in the passage 95 acts to urge the plungers |16 and |11 inwardly. One plunger will be blocked by the valve member 91, and the other plunger will be projected into the path of the other end of the valve member to prevent reversal of the valve 11 at the time past neutral position. Should the pilot valve 18 be reversed during the indexing operation, for example, after a cross feed through a portion of the normal indexing movement to complete the feed across the work, it will condition the direction valve 11 for reversal but at the time will cause the valve 11 to move into neutral position so as to stop further cross feed. After completion of the indexing operation, as determined by the opening of the valve 96, the pressure in the passage 95 will be dissipated to relieve the plungers |16 and |11, and thereupon the direction valve 11 will complete its reversal. However, indexing in the reverse direction will not occur until the Work carriage 3 has completed its final traverse .along the edge of the work and pressure fluid is again supplied to the passage 95.

The normal indexing or cross feed is rapid and intermittent. A normally open hand switch |02 is available to complete a circuit from the line |62 to the line |64 to shunt the time switch |63. When the switch |82 is closed, the solenoid |56 is constantly excited, and cross indexing is rapid and continuous and independent of the movement of the carriage' 3. Continuous slow speed indexing, especially adapted for dressing and setting-up operationsmay be obtained at will by actuating the lever |49 to close the valve |40. This requires the indexing fluid to pass through the adjustable restriction |39, and hence results in a reduction in the rate of fluid supply for indexing purposes. At the same time, a mercury switch |83 on the lever |49-is closed to shunt the time switch |63 across the lines |62 and |64 so as to effect continuous excitation of the solenoid |56.

To provide means for shifting or indexing the tool slide 68 manually, the idler gear |29a is fixed on the lower end of a vertical stub shaft |84 (Figs. 10 and 1l) journaled in the tool head 64. A worm gear |85 is fixed on the upper end of the shaft |84, and is adapted to be engaged by a worm |86 when manual adjustment is desired. The worm |86 is fixed on a shaft |81, which extends eccentrically through and is joumaled in the ends of an elongated sleeve or tube |88, and which is provided with a hand wheel |89 at the front end. The tube |88 is supported for rotary adjustment by means of a hand lever |90 in the front wall of the head 64, and at the rear end in a bracket |9|. The arrangement is such that upon rotation of the tube |88 into one position. as shown in Fig. 10, the worm |86 will mesh with the worm gear |85 to complete the manual drive connection from the shaft |81 to the gear rack |30, and upon rotation of the tube through 180 in a counterclockwise direction as viewed from the front, the worm will be disengaged from the worm gear to interrupt the drive connection.

Provision is also made for disabling the automatic indexing means upon connection of the manual drive. Interposed in the line |6| is a normally open switch |92 which is mounted on a bracket|93 within the tool head 64, and which is adapted to be actuated into closed position by flexing a leaf spring |94 on the side of the switch housing. A collar |95 is fixed on the shaft |81, and is movable into engagement with the spring |94 to close the switch |92 upon rotation of the tube |68 to separate the worm 86 from the worm gear |85, and to permit opening of the switch when the worm is engaged with the worm gear. It will be seen that when the switch |92 is opened, the solenoid |56 cannot be energized, and hence both ends oi' the cross feed cylinder 12 are connected to exhaust to permit manual adjustment of thev slide 68.

position.

tomatically operable upon movement of said second element into a predetermined position of travel to move said control valve for an adjustable predetermined interval of time into closed 2. In a machine tool, in combination, a reciprocable carriage, a machine element movable transversely of said carriage, a hydraulic'motor for translating said element in an indexing movement, asource of motive iiuid under pressure, means including a ow passage for directing uid from said source to said motor, a by-pass passage for diverting fluid from said now passage, an indexing control valve for connecting and disconnecting said passages, and means automatically operable upon lmovement of said carriage into a predetermined position to close said valve for a predetermined time interval and thereby cause the pressure uid to actuate said motor through a distance dependent on the time and rate of fluid supply through said flow passage,

3. In a machine tool, in combination, a reciprocable carriage, a machine element movable transversely of said carriage, a hydraulic motor for translating said element in an indexing .movement a source of motiveliluid under pressure, means including a flow passage for directing fluid from said source to said motor, a bypass passage for diverting iluid from said now passage, an indexing control valve adapted when open to connect said passages so as to divert iluid from said motor and when closed to disconnect said passages so as to cause the pressure iluid supplied through said flow passage to actuate said motor, and means operable in synchronism with said carriage for adjusting said valve into open and closed positions.

4. In a machine tool, in combination, a reciprocable carriage, a machine element movable transversely of said carriage, a hydraulic motor for translating said element in 'an indexing movement, a source of motive uid under pressure, means including a ilow passage for directing fluid from said source to said motor, a bypass passage, an indexing control valve adapted when open to connect said passages so as to divert fluid from said motor and when closed to disconnect said passages so as to cause the pressure fluid supplied through said ilow passage to actuate said motor, springy means normally tending to urge said valve into open position, and means automatically operable upon movement of said carriage into a predetermined position to move said valve into closed position and to maintain said valve in closed position for a predetermined period of time.

5. In a machine tool, in combination, a recipfor translating said element in an indexingv movement, a source of motive fluid under pressure, means including a flow passage for directlng iluid from said source to said motor, a bypass passage, an indexing control valve adapted when open to connect said passages so as to divert uid from said motor and when closed to disconnect said passages so as to cause the pressure fluid supplied through said ilow passage to actuate said motor, spring means tending to urge said valve into open position, and means automatically operable to periodically close said valve respectively upon successive reversals of said carriage, said last mentioned means in' each operation permitting said spring means to return said valve to full open position after a predetermined time delay.y

6. In a machine tool, in combination, a slidable member, a hydraulic piston and cylinder motor for translating saidmember, a pump for supplying a iluid medium under pressure, a direction valve adjustable selectively into oppOsite end positions to connect said motor reversibly to said source, and adjustable into intermediate neutral position to disconnect said motor' from said source, a normally open by-pass valve interposed between said direction valve and said source and adapted when open to-divert the pressure fluid from said motor, and when in closed position adaptedv to direct the uid under pressure' from said source through said direction valve to said motor, means normally tending to open said bypass valve, normally inactive electromagnetic means for moving said by-pass valve into closed position against the action of said means, and means for, effecting excitation of said electromagnetic means.

7. In a machine tool, in combination, a slidable member, a hydraulic piston and cylinder motor for translating said member, a pump for supplying a iuid medium under pressure, a direction valve adjustable selectively into opposite end p0- sitions to connectl said motorreversibly to said source, and adjustable into intermediate neutral position to disconnect said motor from said source, a normally open by-pass valve interposed between said direction valve and said source and adapted when open to divert the pressure fluid from said motor, and when in closed position adapted to direct thel iiuid under pressure from said source through said direction valve to said motor, spring means normally tending to open said by-pass valve, normally inactive electromagnetic means for moving said by-pass valve into closed position against the action of said spring y adapted when open to provide an unrestricted Y path to said by-pass valve, and when closed to cause the fluid to pass through said orice, and means for opening and closing said last mentioned valve.

8. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of iluid under pressure adapted to be connected through a ow passage to said motor, a drain passage, an index control valve interposed in said supply passage and adapted when open to connect said supply passage to said drain passage and when closed to interrupt said connection, spring means tending to move said valve into open. position, a solenoid-operable to for said solenoid including a normally open timedelay switch, an energizing circuit for said timedela.; switch including a normally open control switch, and means automatically operable to' close said control switch momentarily upon movement of said carriage into'either end position.

9. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of fiuid under pressure adapted to be connected through a flow passage to said motor, a drain passage, an index control valve interposed in said supply passage and adapted when opento connect said supply passage to said drain passage and when closed to interrupt said connection, means tending to move said valve into open position, a solenoid operable to move said valve into closed position against the action of said means, an energizing circuit for said solenoid including a normally open time-delay switch, an energizing circuit for said time-delay Vciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of fluid under pressure adapted to be connected through a flow.passage to said motor, a restricted adjustable oriflce in said passage for retarding the supply of fluid, a valve in said passage in parallel to said orice and adapted when open to permit a more rapid supply of fluid, a drain passage, an index control valve interposed in said supply passage and adapted whenopen tofconnect said supply passage to said drain passage and when closed to interrupt said connection, spring means tending to move said valve into open position, electromagnetlmeans operable when energized to move said valveinto closed position yagainst the action of said spring means, an energizing circuit for said electromagnetic means including a normally open time-delay switch, an energizing circuit for saidtime-delay switch including a normally open control switch, means automatically operable to close said last mentioned switch momentarily upon movement of said carriage into a predetermined position, a branch circuit including a normally open switch shunting said time-delay switch, and manual means for opening and closing said first mentioned valve and simultaneously therewith opening and closing said last mentioned switch.

11. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of uid under pressure A adapted to be connected through a flow passage to said motor, a restricted adjustable orifice in said passage for retarding the supply of fluid, a

valvein said passage in parallel to said orifice and adapted when open to permit a more rapid supply ofuid, an index control valve adapted in normal position to prevent the flow of fluid under pressure to said motor and in operative position to cause the flow of fluid under pressure to said motor, electromagnetic means operable to etIect movement of said index valveinto operative position, an energizing circuit for said electromagnetic means including a normally open timedelay switch, an energizing circuit for said timedelay switch including a normally open control switch, means automatically operable to close said last mentioned switch momentarily upon movement of said carriage into a predetermined position, a branch circuit including a normally open switch shunting said time-delay switch, a second branch circuit including a switch shunting said time-delay switch, and manual means for opening and closing said first mentioned valve and simultaneously therewith opening and closing said last mentioned switch.

12. In a machine tool, in combination, a reciprocable carriage, a machine element movable transversely of said carriage, a hydraulic motor for translating said element in an indexing moverient, a source of motive fluid under pressure, means including a ow passage for directing iiuid from said source to said motor, an adjustable orifice in said passage providing a flow restriction, a valve in said passage in parallel to said orice and adapted when open to permit a relatively rapid flow of fluid, means for actuating said valve selectively into open or closed position, an indexing control valve operable in normal position to prevent the iiow of fluid under pressure to said motor, and in operative position to permit such flow, and means automatically operable upon movement of said carriage into a predetermined position to effect movement of said control valve out of said normal positions for a predetermined period of time.

13. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of fluid under pressure, a reciprocable direction valve adjustable reversibly to connect said motor reversibly to said source and having an intermediate neutral position to disconnect said motor from said source, an index control valve for causing the supply of a predetermined quantity of fluid from said source to said direction valve, two pistons coacting respectively with opposite ends of said reversing valve to adjust the latter, a pilot valve automatically operable upon movement of said slide into opposite end positions to direct fluid under pressure respectively to said piston, and two stop plungers adapted for movement respectively into paths of said pistons to limit reversal of said direction valve past neutral position, and means for hydraulically actuating said plungers simultaneously with the supply of fluid under pressure to said direction valve.'

14. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of fluid under pressure, a reciprocable direction valve adjustable reversibly to connect said motor reversibly to said source and having an intermediate neutral position to disconnect said motor from said source, an index control valve for periodically causing the supply fluid under pressure from said source to said direction valve, two pistons slidable in two pressure responsive stop plungers recipro-r cable in said chambers and each being movable into the path of the adjacent piston when said direction valve is in or on the remote side of neutral position, whereby said pilot valve upon actuation is eiective initially to cause movement of said 'direction valve into neutral position, and upon subsequent cessation of the supply of pressure fluid to said direction valve to complete the reversal of said direction valve.

15. In a hydraulic transmission, a direction valve comprising, in combination, a body formed with a valve bore and with coaxial cylinders opening to opposite ends of said bore and with a pressure inlet port, control ports respectively at opposite sides of said inlet port and a drain port, and with two transverse bores intersecting the outer ends of said cylinders and connected at their outer ends to said inlet port, a reciprocable valve plunger in said valve bore and adapted in neutral position to block said control ports from said inlet port and in opposite end positions to connect said control ports respectively and reversibly to said inlet and drain ports, two pistons coacting with opposite ends of said plunger and having free beveled ends slidable respectively in said cylinders, two stop plungers slidable in said transverse bores and having beveled ends adapted for engagement with the beveled ends of said pistons to locate said valve plungers in neutral positions upon initiating reversal thereof when pressure is available at said inlet port, and means for eiecting shifting of said valve plunger.

16. In a machinetool, in combination, a support, a slide mounted on said support, a piston and cylinder motor for translating said slide, a drain, a source of fluid under pressure, a direc- 19. 'Ina machine tool, in combination, a reciprocable carriage, a machine element movable transversely of said carriage, a hydraulic motor for translating said element in an indexing when open to\c'onnect said passages so as to divert fluid from said motor and when closed to disconnect said passages so as to cause the pressure iluid supplied through said flow passage to tion valve for connectingopposite ends of said motor respectively and reversibly to said source and said drain, valve means normally connecting said source to saiddraln and being periodically operable to discount said source from said drain, means responsive to the movement of said slide for reversing said direction valve, and manual means selectively available for translating said slide and being operable to disable said valve means.

17. In a machine tool, in combination, a s upport, a slide mounted on said support, a mechanical drive for translating said slide and including a worm wheel, a worm adapted to engage said wheel and a shaft for rotating said worm, and a tube mounted for rotary adjustment in said support and eccentrically supporting said shaft, said tube being rotatable to move said worm into and out of meshing engagement with said wheel.

l8. In a machine tool, in combination, a reciprocatory carriage, a slide movable transversely of said carriage, a hydraulic motor for translating said slide, a source of iluid under pressure, a direction valve adjustable reversibly to connect said motor reversibly to said source and having an intermediate neutral position to disconnect said motor from said source, an index control valve for periodically causing the supply of a predetermined quantity of uid from said source to said direction valve, and means auto- 4matically operable upon movement of said slide into a predetermined position to effect movement of said direction valve initially into neutral position, and then upon interruption of the supply of iluid under pressure to said direction valve to complete the reversal of said direction valve.

actuate said motor, and means normally tending to maintain said valve in open. position, and being automatically operable upon movement of said carriage into a predetermined position to move said valve into closed position ,and to maintain said valve in closed position for a predetermined period of time.

'20. In a machine tool, in combination, a reversibly translatable carriage, a slide movable relatively to said carriage, a hydraulic motor for translating said slide, a source of iiuid under pressure adapted to be connected through a flow passage to said motor, a drain passage adapted to discharge fluid from said motor, an index control valve associated with one of said passages, said valve having a normal position in which it is eiiective to prevent the displacement of uid in said motor and havingl an operative position in which it is effective to cause the supplyv of uid from said source to said'motor, means including an electromagnetic actuating element and nor.- mally maintaining said valve in said normal position and being operable upon excitation of said -electromagnetic element to move and maintain said valve in said operative position, an energizing 'circuit for said electromagnetic element including a normally open time-delay switch, an

energizing circuit for said time-delay switch including a normally open control switch, means automatically operable to close said control switch temporarily upon movement of said carriage into a predetermined position, and a second energizing cir-cuit for said electromagnetic element including a normally open control switch and shunting said time-delay switch.

21. In a machine tool, in combination, a reversibly translatable carriage, a slide movable relatively to said carriage, a hydraulic motor for translating said slide, a source of iluid under pressure adapted to be connected through a flow passage to said motor, a drain passage adapted to discharge fluid from said motor, an index control valve associated with said ilow passage, said valve having a normal position in which it is effective to prevent the displacement of fluid in said motor and having an operative position in which it is effective to cause the supply of iluid from said source to said motor, hydraulic means independent of said valve for actuating said carriage, electromagnetic means operable upon excitation to move said valve into said operable position and upon deenergization to release said valve for movement into said normal position, an energizing circuit for said electromagnetic means adapted to be closed automatically for a predetermined period of time upon movement of said carriage into a predetermined position, and a parallel energizing circuit for said electromagnetic means adapted to be closed independently of the position of said carriage.

HENRY F. PATRICK.

CERTIFICATE OF C ORRECTI ON APatent No. 2,276, 625. March 17, 191+2.

HENRY F. lPA TRICK.

Y It is hereby certified that error appears inthe printed specification ofthe above numbered patent requiring correoti on as follows: Page 5,A seoond`co1umn, line 12for "passages'lY and 159" read "passages 15.7 and 59"; page?, first column, line h2, claim 16, for "discount" read --disconnect;. and thaty the said Letters Patent should oe read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of May, A. D. 1914.2.

Henry Ven Arsdale, (569.1) I Acting Commissioner of Patents. 

